Ž . The ability of the VLF-R Resistivity method to provide quantitative subsurface resistivity information is examined. The Ž . frequencies used in conventional VLF 15 to 30 kHz provide the deepest penetrations of the multi-frequency, extended method of RadioMT. Both methods are considered. VLF data, being effectively single frequency, are insufficient to resolve Ž . Ž . one-dimensional 1D vert...

[1] ELF/VLF radio waves (300 Hz to 30 kHz) have been successfully generated via modulated HF (3–10 MHz) heating of the lower ionosphere in the presence of natural currents, most recently with the HAARP facility in Alaska. Generation is possible via amplitude modulation or via two techniques involving motion of the HF beam during the ELF/VLF cycle, known as beam painting and geometric modulation...

[1] It is well established that Extremely Low Frequency (ELF, 0.3–3 kHz) and Very Low Frequency (VLF, 3–30 kHz) radio waves can be generated via modulated High Frequency (HF, 3–10 MHz) heating of the lower ionosphere (60–100 km). The ionospheric absorption of HF power modifies the conductivity of the lower ionosphere, which in the presence of natural currents such as the auroral electrojet, cre...

Here, we elucidate the immunological features of both bronchoalveolar lavage fluid (BALF) and vitreous lavage fluid (VLF) samples from patients with histopathologically verified sarcoidosis. In addition, we assess the safety of vitrectomy in sarcoidosis patients by investigating the occurrence of complications and the recovery of visual acuity.Twenty-two eyes of 22 patients with tissue-proven s...

[1] Extremely low frequency (ELF) and very low frequency (VLF) observations have formed the cornerstone of measurement and interpretation of effects of lightning discharges on the overlying upper atmospheric regions, as well as near‐Earth space. ELF (0.3–3 kHz) and VLF (3–30 kHz) wave energy released by lightning discharges is often the agent of modification of the lower ionospheric medium that...

ELF/VLF waves can be generated via amplitude modulated HF heating of the auroral electrojet, which turns a patch of ionospheric currents into a radiating antenna. A new, more powerful technique, termed `geometric modulation', involves scanning the HF beam in geometric patterns with no power modulation. Utilizing results obtained from the HAARP facility, we show that geometric modulation enhance...

The measurement of Very Low Frequency Electromagnetic (VLF-EM) is important in many different applications, i.e, environmental, archeological, geotechnical studies, etc. In recent years, improving and enhancing VLF-EM data containing complex numbers (bivariate) was presented by several authors in order to produce reliable models, generally using univariate empirical mode decomposition (EMD). Ap...

Spectral analysis of cardiovascular signals has been extensively used to investigate circulatory homeostatic mechanisms. However, the nature of very low-frequency (VLF) fluctuations remains unclear. Because we previously observed enhanced VLF fluctuations in blood pressure (BP) in the sympathectomized rat (a model characterized by markedly increased plasma epinephrine levels), the aims of our s...

We studied healthy males challenged with a 900 Cal test beverage and correlated EE with the raw (ms(2)) and normalized units (nu) of total power (TP), low frequency/high frequency (LF/HF) and VLF spectral power of heart rate variability (HRV). The correlations were evaluated during 20 min of normal breathing (NB, control) and 20 min of paced breathing (PB) at 12 breaths·min(-1) (0.2 Hz). EE was...

because of urgent needs of groundwater resources in the tochal region of north tehran, an integration of electric and electromagnetic methods was applied to investigate the location and the direction of water bearing fractures. first, the vlf electromagnetic profiling was performed on suitable places and two locations were detected for supplementary resistivity surveys. then, a number of vertic...